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The Dolby Surround Sound Enhancer

A Review On: Spider Surround Pro

Spider Surround Pro

Rated # 128 in Portable Amps
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Review Details:
Audio Quality
Posted · Updated · 2135 Views · 4 Comments

Pros: Dolby Pro Logic II surround sound effect for movie and music

Cons: Hiss, volume reduction.

Last time when we take a look at Spider, they were mainly a cable and IEM company. Now however, their product range covers everything from full sized headphone and small portable amps, including the Surround Pro that will be reviewed here.





DSP: Dolby Pro Logic II

Input/Output: 3.5mm Audio Jacks

ADC Audio Performance:

93dB SNR

81dB THD

Sampling Frequency: 8Hz-96kHz

DAC Audio Performance:

100dB SNR

90dB THD

Sampling Frequency: 8Hz-96kHz







Accessories and Build Quality

The amp itself comes fairly well packed. Inside, you will find the amp, a back-clip ‘holster’, a short TRRS-to-TRRS interconnecting cable, as well as a microUSB charging cable. The overall build quality is actually quite solid, though nothing really spectacular to write home about. It is mainly hard plastic with aluminum trimming. Due to the rounded protrusion on the back (which seems to be the battery compartment), the holster actually are front facing, but it shouldn’t really be an issue. Though the amp comes with a TRRS cable, it doesn’t actually support mic and remote pass-through. It would have been great if it did, as I would imagine the Surround Pro will most appeal to mobile device user, especially tablet and phablet user who like to watch movie. Beside the power switch, there only other switch is for selecting Normal, Music or Movie mode. Normal mode is basically a pass through function with no Dolby processing, while Movie and Music movie each has different Dolby optimization to create a virtual 5.1 surround sound.


If there is one thing I don’t like about the design, it will be the lack of power on/off indicator. The only LED on the device is for charging only, so if you forget that you have left it on or accidentally turn it on, the battery will be drained completely.



Surround Pro with the clip.




Gain, Hiss and EMI

So far we have been referring to the Surround Pro as an amp, but the fact is it is not much of an amp actually, as it has a -5dB gain in Normal mode. This means it actually reduces loudness instead of increasing it. The Movie and Music modes are no better as well. Hiss is actually fairly noticeable on the Surround Pro, especially in quiet passage and when music is not playing. Good thing is that it isn’t so loud that it is audible when music is playing. EMI is very mild, so not a problem at all.


Sound Quality

As usual, I gave the Surround Pro an RMAA test just to get some basic information. The device measures surprisingly good in Normal mode. Actually it isn’t that much of a surprise given it doesn’t really amplify the sound. I didn’t bother to measure it under Music or Movie modes as I don’t expect RMAA to measure them correctly. The output impedance is a very good 1 ohm, and the current output is actually quite good as well.








So if Surround Pro isn’t much of an amp, what is it? Well, it is pretty much a hardware EQ system tailored for soundstage enhancement, similar to the discontinued JVC SU-DH1 but with lesser features (plus lower price tag).  Basically the device converts the input analog signal to digital, toss in some Dolby Pro Logic II magic, and then reconverts it back to analog signal.


So how does it sound? Well, quite excellent actually. You can’t really treat it as an amp and want it to sound neutral or transparent. That’s not what the Surround Pro is about. But once you leave the perception of amp behind, you can start enjoy the 5.1 channels simulation. The truth is I really not sure how the 5.1 thingy works, but the surround sound effect is fairly convincing, especially for movie. Action film starts to really come alive on my smartphone with the Surround Pro and a pair of headphone. While music also benefits from the surround sound effect, I tend not to care as much about it. Yes, it is more fun to listen to stereo music with the effect – but I have no problem listen to stereo as well, given I am not seeking a particularly fun experience with music as much as I do with movie. Don’t get me wrong though, if you are really seeking for the extra fun element, the Surround Pro does deliver that aspect very well. The Music mode is however not the same as the Movie mode. Music mode tends to be more about get a wider, rounder, more forward and immersive soundstage, while Movie is really about the surround sound effect like a home theater system. There is no restriction on which mode you should use for what though – while I do recommend Movie mode for movie only, Music mode tends to work both ways, depends on how you like your music.



Surround Pro and Nano 7G



While I won’t classify the Surround Pro as an audiophile gears, it is still quite a useful gadget to your average headphone user in the current mobile entertainment era where you get to watch movie and video on-the-go.  To overcome the hiss issue and for proper voltage (volume) gain, I really suggest you use the Surround Pro in between the source and an amp, even a small one. It will be like infusing your setup with some well-tuned Dolby effect (*and not to be confused with the often over-the-top SRS WOW effect). Yes, you will be double amping - but as I have mentioned, the device itself does have a very clean RMAA result and therefore shouldn’t degrade the sound quality by much. Consider the fun and joy of good sounding entertainment on the other end, I’ll say it is quite worth it.


A thank to Spider International for the sample.


If not for the hiss (and I tend to use sensitive CIEMs) I'd definitely jump on this for movie watching on the computer.
A little disappointed because I am saving money and looking for a good Surround DAC/AMP to pair with my Sennheiser HD598 for movies and games, but that looks like most of sub $100-$200 USB Dobly Surround DAC/AMPs on the market suffer annoying hiss and noise. Ok, I keep my waiting. Nice review by the way Clieos.
Ah yeah. Can I ask you one thing. You had a Jdslabs C421, an old versions right. Could you please measure how many mW or W that a C421 can produce at 50Ohm because I intend to use my C421 to drive a Orthos headphone such as Mad Dog or Alpha Dog. Thanks.
To address the hiss issue, it seems the best thing to do is to add an amp after the Surround Pro. Of course, you can still use it as it is as hiss isn't that bad that will affect the quality of the movie.
As for JDS C421 - there are two factors that define power: voltage and current output. C421 has a (high) gain of 17dB, so it should be okay voltage wise unless the headphone is very insensitive. However, the current output is quite weak. I am really not sure how that will translate to performance on the Orthos. It will take an oscilloscope to measure max power output and I don't have one.
guys, for laptops and pc I recommend Asus Xonar products with Dolby Headphone System.
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